/*

TagCloud jQuery plugin

A dynamic JavaScript tag/keyword cloud plugin for jQuery, designed to use with Ajax:
the cloud is generated from an array.

MIT license.

Schaffer Krisztián
http://woophoo.com

Usage:
------

Call it on a jQuery object created from one element and pass an array of
objects with "tag" and "count" attributes. E.g.:

var tags = [{tag: "computers", count: 56}, {tag: "mobile" , count :12}, ... ];
$("#tagcloud"}.tagCloud(tags);


Configuration:
--------------
Optionally you can pass a configuration object to tagCloud as the second
parameter. Allowed settings are:

sort: Comparator function used for sort the tags before displaying, or false if
   no sorting needed.

   default: sort by tag text using
          function (a, b) {return a.tag < b.tag ? -1 : (a.tag == b.tag ? 0 : 1)

click: Event handler which receives the tag name as first parameter
   and the original click event as second. The preventDefault() is called
   on event before passing so don't bother.

   default: does nothing:
          function(tag, event) {}


maxFontSizeEm: Size of the largest tag in the cloud in css 'em'. The smallest
   one's size is 1em so this value is the ratio of the smallest and largest
   sizes.

   default: 4


Styling:
--------
 The plugin adds the "tagcloudlink" class to the generated tag links. Note that
an "&nbsp;" is generated between the links too.


Originally based on DynaCloud v3 by
Johann Burkard
<http://johannburkard.de>
<mailto:jb@eaio.com>

CHANGES:
05 sept. 2008
- Improved normalization algorithm - better looking font sizes
- New settings: click, maxFontSizeEm
- Documentation

04 sept. 2008
- Initial version

*/

jQuery.fn.tagCloud = function(cl, givenOptions) { //return this.each( function() { //like a real jQuery plugin: run on on each element
    if (!cl || !cl.length)
        return this;

    // Default settings:
    var defaults = {
        sort: function(a, b) { return a.tag < b.tag ? -1 : (a.tag == b.tag ? 0 : 1) }, //default sorting: abc
        click: function(tag) { },
        maxFontSizeEm: 2.3
    }

    var options = {};
    jQuery.extend(options, defaults, givenOptions);

    // calculating the max and min count values
    var max = -1;
    var min = cl[0].count;
    $.each(cl, function(i, n) {
        max = Math.max(n.count, max);
        min = Math.min(n.count, min);
    });

    //if (options.sort) {
    //  cl.sort(options.sort);
    //}

    //Normalization helper
    var diff = (max == min ? 1    // if all values are equal, do not divide by zero
                           : (max - min) / (options.maxFontSizeEm - 1)); //optimization: Originally we want to divide by diff
    // and multiple by maxFontSizeEm - 1 in getNormalizedSize.
    function getNormalizedSize(count) {
        return 0.55 + (count - min) / diff;
    }

    // Generating the output
    this.empty();
    for (var i = 0; i < cl.length; ++i) {
        var tag = cl[i].tag;
        var href = cl[i].href;
        var tagEl = jQuery('<a href="' + href + '" class="tagcloudlink" style="font-size: '
                           + getNormalizedSize(cl[i].count)
                           + 'em">' + tag + '<\/a>')
                  .data('tag', tag);

//        if (options.click) {
//            tagEl.click(function(event) {
//                event.preventDefault();
//                options.click(jQuery(event.target).data('tag'), event);
//            });
//        }

        if (cl.length - 1 != i) {
            this.append(tagEl);
            //this.append(tagEl).append(" - ");
        }
        else {
            this.append(tagEl).append("");
        }

    }
    return this;
    //})
}